DISSIMILAR VACUUM BRAZING OF ADDITIVE MANUFACTURED 17-4PH STAINLESS STEEL TO CONVENTIONAL 304 AND 17-4 STAINLESS STEEL BY BNI-2 BRAZING FILLER MATERIAL

Vacuum brazing process of 17-4PH stainless steel, which was manufactured using additive manufacturing, as well as conventional AISI304 and 17-4PH stainless steel alloys was investigated. The brazing process was conducted at 1050°C for 20 minutes under 10-6 Torr, using BNi-2 filler material. Various aspects of the vacuum brazed parts were analyzed, including their microstructure, wetting behavior and mechanical strength. To evaluate the wetting behavior, the contact angle and wetted area were measured using optical microscopy. The microstructures were examined using Scanning Electron Microscopy and Energy Dispersive Spectroscopy techniques. Additionally, tensile testing was performed on the joints to assess the influence of surface roughness and brazing of different materials on the strength of the brazed parts.Mechanical Engineerin

Evaluation of natural dyeing of leather with Rubia tinctorum extract [Derinin Rubia tinctorum ekstrakti{dotless} ile dogal boyanabilirliginin degerlendirilmesi]

The aspect of producing leather and textile products without impacting on the ecological balance, affecting both human and environmental health, is an important focal point to be pursued. Therefore, to address some of these issues a study was conducted to evaluate the efficiency of dyeing leather with madder, which is a 100% natural dyestuff from the extract of Rubia tinctorum and ascertain its friendly attributes to the environment. Treatment designs in the study included pre and post mordanting methods which were applied to selected types of leather and subsequently subjected to three different mordants: potassium aluminium sulphate [KAI(SO 4) 2.12H 2O], copper sulphate [CuSO 4.5H 2O] and ferro sulphate [FeSO 4.7H 2O]. This approach was done to potentially obtain different colors and improve color fastnesses. In this study, the investigation was based on two primary source of tanned material, chrome and vegetable tanned leathers. Color measurements of the dyed leathers were carried out using a Minolta CM-508d brand spectrophotometer. On the other hand, dyestuff exhaustions were determined using a Shimadzu UV-1601 PC UV-Visible spectrophotometer. On the finished leather products, parameters such as color fastness to rubbing was determined with, the TS EN ISO 11640, color fastness to perspiration with, the TS EN ISO 11641, and color fastness to light with, the ISO 105-B02 standard method. Moreover these parameters were comparatively analyzed and reported. The results eventually indicated that the obtained color and color fastness values varied according to; the type of tanning method, mordanting method, and mordant type. Most of the result values obtained were generally at satisfactory levels which were between 3/4 and 5 fastness values. Different extraction methods, different mordants, and mordanting methods to be carried out in future are suggested so as to optimize the results of the current study

A novel approach in leather finishing: Surface modification with flock fibers

In recent years, finishing has begun introducing an extraordinary touch and appearance to the surface of leathers by surface modification. Because some superficial anomalies cannot be recovered by conventional finishing procedures, those can only be drawn on by coating techniques. Coating aims at obtaining an alluring product, which must both recover the surface anomalies and be compatible with the leather characteristics.This study is for valorization of leathers with inferior quality, which contain surface defects, thereby being aimed at improvement of the surface characteristics. The product should have ease of use, as well as giving a fashionable look and touch to flocked fibrous surfaces, whether applied to synthetic leather types or Alcantara. For covered and patterned fibrous surfaces, the experimentations of different flock formulations with different binder types were executed, superficial characteristics were imaged with optoanalytical techniques and the fiber adhesion onto the surface was examined by abrasion tests. The research results showed that polyurethane binder had acceptable qualities for bags, footwear, garments and accessories and yielded superior binding characteristics compared to acrylic binder. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav

Modification of leather surface characteristics with fiber coating: Flocking of leather

BASF;Clariant Iberica;Colorantes Industriales;Cromogenia Units;Dercosa;et al.31st Congress of the International Union of Leather Technologists and Chemists Societies, IULTCS 2011 -- 27 September 2011 through 30 September 2011 -- 109691The fact that leather's surface of use is brought touch and appearance in an unusual way has become the main objective of finishing in recent years. Because some surface defects cannot be overcome with a classic type finishing, it possible for them to be evaluated with coating techniques. Coating must be aimed at obtaining an alluring product besides its compatibility with the leather properties' being important and in addition to its overcoming the surface defects. In the study, we conducted some studies on the evaluation of the leathers, which are of low quality and contain surface defects, aiming at obtaining different surface characteristics. We aimed to bring ease of use and alternative appearance and touch by creating a fibrous surface through the covering of the flocked, which is an important group of synthetic leathers, and alcantara's applicaitons on leather. In order to obtain an effective fibre surface in different patterns and smooth applicaitons, different binder types, flock formulations and flock fibres were tried, their characteristics were determined thanks to imaging techniques and the sufficiency of fibres' bindings were examined through some physical tests. According to the results, it was observed that in the products of bag, shoes, dress and accessories, on which fantasy appearance and different patterns were applied, polyurethane binder is at the sufficient level and it brings in more superior binding characteristics than acrylics binder